Terminal and a base station for mapping or receiving a demodulation reference signal

Abstract

Provided is a user terminal which is used in a future wireless communication system which bundles a plurality of slots (sub-frames) in the time direction. When applying bundling, in the leading slot, Additional DMRS (Demodulation Reference Signal) is mapped according to channel quality (factors which lead to a deterioration in quality, such as Doppler shift, propagation environment, etc.), and in second and subsequent slots, the existence of Additional DMRS mapping or the mapping position is selected on the basis of rules concerning Additional DMRS mapping. The control unit (203) of the user terminal (20) specifies, in second and subsequent slots, the existence of Additional DMRS mapping and the mapping position on the basis of the aforementioned rules.

The invention claimed is: 
     
       1. A terminal comprising:
 a processor that maps a front-loaded demodulation reference signal (DMRS) and an additional DMRS to a physical uplink shared channel (PUSCH); and 
 a transmitter that transmits the PUSCH being with aggregated multiple slots along a time direction when the terminal is configured with aggregation, 
 wherein, the processor maps the front-loaded DMRS to the same symbol position in a first half of each of the aggregated multiple slots; and 
 when the additional DMRS is mapped to a top slot of the aggregated multiple slots, the processor maps the additional DMRS in each of a second and later slots of the aggregated multiple slots to the same symbol position as in the top slot. 
 
     
     
       2. The terminal according to  claim 1 , wherein:
 the processor maps the additional DMRS to a symbol behind the front-loaded DMRS in the each of the aggregated multiple slots. 
 
     
     
       3. A terminal comprising:
 a receiver that receives a physical downlink shared channel (PDSCH) including a front-loaded demodulation reference signal (DMRS) and an additional DMRS, the PDSCH being with aggregated multiple slots along a time direction when the terminal is configured with aggregation; and 
 a processor that performs reception processing by referring to the front-loaded DMRS and the additional DMRS, 
 wherein, the front-loaded DMRS is mapped to the same symbol position in a first half of each of the aggregated multiple slots; and 
 when the additional DMRS is mapped to a top slot of the aggregated multiple slots, the additional DMRS is mapped in each of a second and later slots of the aggregated multiple slots to the same symbol position as in the top slot. 
 
     
     
       4. The terminal according to  claim 3 , wherein:
 the additional DMRS is mapped to a symbol behind the front-loaded DMRS in the each of the aggregated multiple slots. 
 
     
     
       5. A base station comprising:
 a receiver that receives a physical uplink shared channel (PUSCH) including a front-loaded demodulation reference signal (DMRS) and an additional DMRS, the PUSCH being with aggregated multiple slots along a time direction when the terminal is configured with aggregation; and 
 a processor that performs reception processing by referring to the front-loaded DMRS and the additional DMRS, 
 wherein, the front-loaded DMRS is mapped to the same symbol position in a first half of each of the aggregated multiple slots; and 
 when the additional DMRS is mapped to a top slot of the aggregated multiple slots, the additional DMRS is mapped in each of a second and later slots of the aggregated multiple slots to the same symbol position as in the top slot. 
 
     
     
       6. The base station according to  claim 5 , wherein:
 the additional DMRS is mapped to a symbol behind the front-loaded DMRS in the each of the aggregated multiple slots.